An OFDM multiple input multiple output (MIMO) signal may exhibit high peak to average power ratios (PAPR) in both time and frequency domains. Traditionally, a time domain gain control scheme is used to get constant signal level to maximize finite precision performance while minimizing hardware complexity. However, in an OFDM MIMO system, a frequency domain signal (i.e., the signal after FFT) may still show high PAPR even after time domain gain control is applied.
The high PAPR values of frequency domain OFDM MIMO signals may require a large dynamic range for hardware architectures of OFDM MIMO decoders to preserve their original performance, which is expensive.